Though megastar Amitabh Bachchan is upset over his son Abhishek being left out from the Earth Hour event in the capital, the junior Bachchan has clarified he missed the function due to "prior shoot commitments".

"I was to be at the India Gate function (Saturday evening) being the ambassador, and all, but prior shoot commitments would not allow me. I'm tucked away in Goa. I had sent a video message for all at the event, thanking them for their participation and support, but for some reason that couldn't be shown, " Abhishek tweeted.

"I hope we never have to celebrate another Earth Hour! I hope we can reverse the effects of global warming! I hope we can spread the message of a greener tomorrow, " he added.

Abhishek was appointed the World Wildlife Foundation (WWF) ambassador for Earth Day, a campaign for the preservation of the earth by shutting off electricity for an hour.

"I'm told that the Earth Hour was a huge success. Well done guys. You'll have done a wonderful job in spreading the news... I believe the function at the India Gate was also very nice and well attended. Kudos to the team at WWF for pulling all this off, " he further posted.